First trial to resolve issue #264

src/Sample/LatinHyperCube.h

@@ -13,23 +13,21 @@ class LatinHyperCube : public SamplingMethod
 public:
     typedef typename std::uniform_real_distribution<double> dist_t;
 
-    LatinHyperCube(double lower, double upper, std::size_t n)
-        : binsize_m((upper - lower) / double(n))
+    LatinHyperCube(double lower, double upper)
+        : binsize_m(0.0)
+        , upper_m(upper)
         , lower_m(lower)
         , dist_m(0.0, 1.0)
     {
-        this->fillBins_m(n);
-        
         RNGInstance_m = RNGStream::getInstance();
     }
     
-    LatinHyperCube(double lower, double upper, int seed, std::size_t n)
-        : binsize_m((upper - lower) / double(n))
+    LatinHyperCube(double lower, double upper, int seed)
+        : binsize_m(0.0)
+        , upper_m(upper)
         , lower_m(lower)
         , dist_m(0.0, 1.0)
     {
-        this->fillBins_m(n);
-        
         RNGInstance_m = RNGStream::getInstance(seed);
     }
 
@@ -44,6 +42,13 @@ public:
         ind->genes[i] = map2domain_m(RNGInstance_m->getNext(dist_m));
     }
     
+    void allocate(std::size_t n) {
+        
+        binsize_m = ( upper_m - lower_m ) / double(n);
+        
+        this->fillBins_m(n);
+    }
+    
 private:
     double map2domain_m(double val) {
         /* y = mx + q
@@ -77,6 +82,7 @@ private:
     std::deque<std::size_t> bin_m;
     double binsize_m;
     
+    double upper_m;
     double lower_m;
     
     dist_t dist_m;

src/Sample/OpalSample.cpp

@@ -139,9 +139,9 @@ void OpalSample::initialize(const std::string &dvarName,
             size_m = static_cast<FromFile*>(sampleMethod_m.get())->getSize();
         } else if (type == "LATIN_HYPERCUBE") {
             if (Attributes::getReal(itsAttr[SEED])) {
-                sampleMethod_m.reset( new LatinHyperCube(lower, upper, seed, size_m) );
+                sampleMethod_m.reset( new LatinHyperCube(lower, upper, seed) );
             } else {
-                sampleMethod_m.reset( new LatinHyperCube(lower, upper, size_m) );
+                sampleMethod_m.reset( new LatinHyperCube(lower, upper) );
             }
         } else {
             throw OpalException("OpalSample::initialize()",

src/Sample/SampleCmd.cpp

@@ -135,8 +135,8 @@ void SampleCmd::execute() {
         throw OpalException("SampleCmd::execute",
                             "Number of sampling methods != number of design variables.");
 
-
-    std::map< std::string, std::shared_ptr<SamplingMethod> > sampleMethods;
+    typedef std::map< std::string, std::shared_ptr<SamplingMethod> > sampleMethods_t;
+    sampleMethods_t sampleMethods;
 
     std::map<std::string, std::pair<double, double> > vars;
 
@@ -429,6 +429,14 @@ void SampleCmd::execute() {
         boost::shared_ptr<Comm_t>  comm(new Comm_t(args, MPI_COMM_WORLD));
         if (comm->isWorker())
             stashEnvironment();
+        
+        if ( comm->isOptimizer() ) {
+            for (sampleMethods_t::iterator it = sampleMethods.begin();
+                 it != sampleMethods.end(); ++it)
+            {
+                it->second->allocate(nSample);
+            }
+        }
 
         boost::scoped_ptr<pilot_t> pi(new pilot_t(args, comm, funcs, dvars, objectives, sampleMethods, storeobjstr));
         if (comm->isWorker())

src/Sample/SamplingMethod.h

@@ -11,6 +11,22 @@ class SamplingMethod
 
 public:
     virtual void create(boost::shared_ptr<SampleIndividual>& ind, size_t i) = 0;
+    
+    /*!
+     * Allocate memory for sampling. Not every sampling method
+     * requires that.
+     * 
+     * This function is used to reduce memory since only the
+     * sampler ranks need these sampling methods.
+     * 
+     * @param n number of samples
+     */
+    virtual void allocate(std::size_t n) {
+        /* Some sampling methods require a container.
+         * In order to reduce memory only samplers should allocate
+         * the memory
+         */
+    }
 };
 
 #endif
\ No newline at end of file